look back, look over your shoulder くらいでいいと思います。don't look back just keep on walking. 振り返らず前に進め take a look over your shoulder when you start a car. 発進するときは後ろを確認。turn aroundは体をこっちに向けてlook backすることです。look over your shoulder はクビだけを動かします。look over shouldersは単に後ろを振り返るの意味と何かが怖くて振り返るの比喩的な意味があります。
http://www.youtube.com/watch?v=IQtlEeSzTnE 2:46 when you look back,,,,http://bridge-english.blogspot.com/2011/02/kaerimitu.html 顧みる（かえりみる）を英語でなんと言うか？
http://www.youtube.com/watch?v=CWpKkHN8ZcE 1:09 why Tony Blair will always have to look over his shoulder. なぜブレア元首相がいつも怖くて何度も後を振り向かなければならないのか
http://www.youtube.com/watch?v=o0t883OX6r8 0:20 a lot of people were looking over my shoulder to see exactly this was. ここでは肩越しに覗き込むの意味です。
http://www.youtube.com/watch?v=kVQsYDKaDkU&feature=g-vrec 0:56 When I looked over my shoulder and saw the bull I was obviously getting more scared as they were approaching, but at the same time, the adrenaline in me was kicking in.後ろを振り返ったら牛が迫っていてあせったけど、自分の中ではアドレナリンが爆発していた。
練習問題解答
b-5051 looking over its shoulder
